Cleft palate is one of the most frequently occurring birth defects in the United States. Current standards of care emphasize early surgical correction of clefts of the secondary palate (soft and hard) but not primary palate (alveolar ridge). Following surgical repair of the secondary palate, the majority of children experience deficits in speech intelligibility to various degrees. Most of these children exhibit anomalies of the alveolar/palatal vault as a result of either not repairing the primary palate and/or as consequences of repairing the secondary palate (i.e., oro-nasal fistula, growth restrictions). The overarching hypothesis of this proposal is that anomalies of the posterior velopharyngeal and anterior alveolar/palatal structures contribute to different speech intelligibility deficits. The specific objectives are to identify the structural and phonetic factors that underlie speech intelligibility in young children with repaired clefts of the secondary palate with or without cleft lip (Aim 1). A single-word intelligibility test will be used to study 150-200 children (age range 4 to 8 years) with cleft palate and 50 children without cleft palate in the same age range. Eleven (11) different phonetic contrasts will be used to determine overall speech intelligibility. It is hypothesized that among all children with cleft palate, velopharyngeal (VP) followed by alveolar/palatal factors will account for global speech intelligibility. It is further hypothesized that alveolar/palatal factors will contribute to specific phonetic contrast deficits, especially involving backed or palatalized consonants, that have traditionally been attributed to VP factors. Acoustic characteristics of selected phonetic contrasts (Aim 2) and specific alveolar/palatal factors (Aim 3) will also be explored in subgroups of children who exhibit complete and incomplete VP closure. Multiple regression and descriptive discriminant analysis techniques will be employed. The findings are expected to a) provide meaningful data to guide both surgical and behavioral interventions relative to patient selection and/or phonetic contrast priorities, b) suggest a different etiology for frequently occurring backed compensatory articulations, c) advance current trends toward early surgical repair of alveolar clefts, and d) stimulate future clinical trials to investigate the efficacy of early surgery to correct structural defects of the primary and/or second palates via single-word intelligibility testing.